Solid ink jet printers were first offered commercially in the mid-1980""s. One of the first such printers was offered by Howtek Inc. which used pellets of colored cyan, yellow, magenta and black ink that were fed into shape coded openings. These openings fed generally vertically into the heater assembly of the printer where they were melted into a liquid state for jetting onto the receiving medium. The pellets were fed generally vertically downwardly, using gravity feed, into the printer. These pellets were elongated and tapered on their ends with separate rounded, five, six, and seven sided shapes each corresponding to a particular color.
Later solid ink printers, such as the Tektronix Phaser(trademark), the Tektronix Phaser(trademark) 300, and the Jolt printer offered by Dataproducts Corporation, used differently shaped solid ink sticks that were either gravity fed or spring loaded into a feed channel and pressed against a heater plate to melt the solid ink into its liquid form. These ink sticks were shape coded and generally small. One system used an ink stick loading system that initially fed the ink sticks into a preload chamber and then loaded the sticks into a load chamber by the action of a transfer lever. Earlier solid or hot melt ink systems used a flexible web of hot melt ink that is incrementally unwound and advanced to a heater location or vibratory delivery of particulate hot melt ink to the melt chamber.
Basic configurations of a four-color ink loader having independent melt plates have been described in previously issued patents such as, for example, U.S. Pat. Nos. 5,734,402, 5,861,903, and 6,056,394. The disclosures of these patents are hereby incorporated by reference in their entirety.
Embodiments include a solid ink supply system for feeding solid ink sticks to an ink jet printer, which includes a housing for receiving and staging the solid ink sticks, at least two supply channels within the housing, at least two key plates covering the supply channels, each of the key plates including an insertion opening for receiving a solid ink stick, and a push block within each supply channel for urging the ink sticks down the supply channels.